"Debacle" comes from the French noun "débâcle," which comes from the verb "débâcler," meaning "to clear," "to unbolt," or "to unbar." That verb is from Middle French "desbacler," which joined the prefix "des-" (equivalent to our "de-," meaning "to do the opposite of") with the verb "bacler" ("to block"). In its original uses, "debacle" meant a breaking up of ice, or the rush of ice or water that follows such an occurrence. Eventually, "debacle" was used also to mean "a violent, destructive flood." Naturally, such uses led to meanings such as "a breaking up," "collapse," and finally "disaster" or "fiasco."